Color photography



Patented Jan.

. UNITED STATES PATENT OFFICE COLOR PHOTOGRAPHY Gustav Wilmanns, Woli'en, Kreis Bitterield, and Adult Sieglitz, Frankiort-on-the-Main-Hcohst, and Alfred Friihlich, Dessan in Anhnlt, Germany, assignors, by mesne assignments, to Agia Ansco Corporation, ljinghamton, N. Y., a corporation of Delaware No Drawing. Application February 20, 1937, fg-isal No. 126,842. In Germany February 2'1,

14 Claims.

Our present invention relates to the art of color photography.

One of its objects is a process of producing photographic color pictures by means of dyestufl components. A further object is the provision of novel photographic materials used for producing the photog.'aphic color pictures. Further objects will be seen from the detailed specification 1'01- lowing hereafter.

It is known that in the production of photographic pictures in, 'color there may be used with advantage as dyestuii components a number of compounds which are characterized by a particularly active methylene group. For example, methylphenylpyrazolone has been 'pro- 0 posed for the color development. This body forms a red dyestufl' picture on the parts where there is a silver precipitate produced by development 01 a silver picture with paradimethylaminoaniline. If for the production of color pictures the silver antidiazotate process according to German Patent 561,867 corresponding to U. S.

Patent 1,963,197 or similar processes working with diazonium compounds are used, one obtains by coupling with acetic acid ester anilides yellow dyestufl pictures.

In addition to the, aforesaid bodies, however, there. are compounds which, notwithstanding that they have a reactive methylene group, are not suitable intermediate products for obtaining photographic color pictures since they do not yield dyestuffs and for that reason cannot be used as components for color development or in certain cases for the treatment with dia'zo-com 3 pounds. Examples of these ineffective bodies are fluorene, benzofluorene, indene, dihydroresorcinol, hydroxythionaphthene, diphenylmethane and cyclohexanol.

This invention is based on the observation that the methylene group in such compounds may be made particularly active if the body is converted into an oxalic acid ester derivative of the compound or derivative thereof. These oxalic acid ester derivatives, which provisionally maybe regardedas compounds oi. the following structure:

, n armmciooc-cooolm :oc'ooooui| behave in the photographic color as do the bodies having the highly reactive methylene groups refered to above. For example, the oxalic acid ester or fluorene of the following formula yields when used as dyestuilf component in' color development a red dyestuii picture of particularly pure tint when dimethylaminoaniline is used as a developer, the oxalic acid ester of indene .cri/

( ro our, 0 0

layer material before exposure, if desired, to the gelatin before or during the preparation of the emulsion, in a form stable to diflusion, eitherin the most finely dispersed form as insoluble compounds or after they have been converted into suitable substitution products which are soluble in water as described in U. 8. Patent applications Ser. No. 10,704 flied March 12, 1935, Ser. No. 72,718 filed April 4, 1936, ser. No. 90,726 'iiled July 15, 1936, and Ser. No. 94,340 filed August 5,1936.

From these emulsions there may be cast a single layer material or a multi-layer material having the layers either on one or 'on both sides of a I support. The support may either consist of a transparent material as for instance Celluloid,

cellulose-acetate or of a light-reflecting material, as for instance paper.

The following examples serve to illustrate the invention:

(1) An exposed silver halide emulsion layer is developed by means of a developer consisting of a solution of 3 grams of p-aminodimethyl-aniline and 1000 cc. of a 3% soda-solution to which are added 1.5 grams of the oxalic acid ester of fluorene.

A red color picture is obtained.

If in the same developer the oxalic acidester of fiuorene is replaced by the oxalic acid ester of indene there is obtained a blue dyestuff image.

(2) An exposed silver halide emulsion layer is developed, fixed and the silver image transformed into an azo-dyestuff image by means of the diazocompound of B-naphthylamine. If this diazo silver image is immersed into a weal: acetic acid solution of the oxalic acid ester of 2.3-benzofluorene, a yellow azo-dyestuif image is obtained.

What we claim is:

1. A light-sensitive silver halide emulsion containing as a dyestuif component for color forming development a compound containing a methylene group activated by substitution of one hydrogen atom thereof by a radical having the following formula C-C-OR II II 0 0 wherein R is an alkyl radical.

2. A light-sensitive silver halide emulsion containing as a dyestui component for color forming development a compound containing a methylene group, said compound being per se insufficiently reactive to form a dye by color forming development but being activated by substitution of one hydrogen atom of the methylene group by a radical having the following formula wherein R is an alkyl radical.

3. A light-sensitive silver halide emulsion containing as a dyestufi component for color forming development a compound containing a methylene group activated by substitution of one hydrogen atom thereof by a radical having the following formula wherein R is an alkyl radical, said dyestuff cornponent containing in addition a radical which renders it fast to diffusion.

4. A light-sensitive silver halide emulsion containing as a dyestuif component for color forming development a compound containing a methylene group selected from the group consisting of fluorene, benzofiuorene, indene, dihydroresorcino1, hydroxythionaphthene, diphenylmethane and cyclohexanol, in which the methylene group is activated by substitution 'of one hydrogen atom by a radical of the following formula wherein R is an alkyl radical.

5. A color forming developer comprising an aromatic amino developing agent and a compound containing a methylene group activated by substitution of one hydrogen atom thereof by a radical of the following formula wherein R is an alkyl radical.

6. A color forming developer comprising an aromatic amino developing agent and a compound containing a methylene group, said compound being per se insufficiently reactive to form a dye by color forming development but being activated by substitution of one hydrogen atom of the methylene group by a radical of the following formula -o-c-on 3 Ii 0 wherein R is an alkyl radical.

7. A color forming developer comprising an aromatic amino developing agent and a compound selected from the group consisting of fluorene, benzofluorene, indene, dihydroresorcinol, hydroxythionaphthene, diphenyimethane and cyclohexanol, in-which the methylene group is activated by substitution of one hydrogen atom by a radical of the following formula Jc J-oR I 0 0 wherein R is an alkyl radical.

8. The method of developing a colored image in a gelatino-silver halide photographic layer which method comprises coupling the developing thereof by a radical having the following formula CCOR

wherein R is an alkyl radical.

10. A light-sensitive silver halide emulsion containing as a dyestuif component for color formation a cyclic compound containing a nuclear methylene group activated by substitution of one hydrogen atom thereof by a radicle having the following formula -C--COR wherein R is an alkyl radicle.

11. A light-sensitive silver' halide emulsion containing as a dyestuif component for color forming development a cyclic compound containing a nuclear methylene group activated by substitution of one hydrogen atom thereof by a radicle having the following formula wherein R is an alkyl radicle.

'e,1ee,suo v *3 12. A light-sensitive silver halide emulsion as wherein the radicle activating said methylene defined in claim 1 wherein the compound conh group is I taining the methylene group is indene and 41-0-0011! 5 wherein the -redicle activating said methylene A 3 6 group 14. The developer defined in claim 'I wherein A 3 the developing agent is p-dlmethyl-aminoaniline. 13. A light-sensitive silver halide emulsion as GUSTAV W o defined in claim 1 wherein the compound con- ADOLF BIEGLITZ- m taining the methylene group is fluorene. and AIJRED FRQHLICE. 

